This invention relates to a coupling device for connection to a plurality of hydraulic conduits which are bunched together to form a multi-core duct. The invention is particularly useful in the hydraulic distribution systems used in mine workings.
In underground mine workings, such as longwall workings having hydraulically advanceable roof support assemblies and other hydraulic appliances, a number of high pressure hydraulic conduits have to be laid within, and pass along, the individual units of the roof support assembly. In the restricted spaces available in mines, however, the installation of the numerous conduits is greatly impeded, particularly as it has to be carried out in such a way that the roof support assembly, and the associated longwall conveyor, can be advanced without damaging these conduits.
Systems are known in which the numerous hydraulic conduits are bunched together to form multi-core hydraulic ducts, interconnected by means of generally cylindrical plug couplings. A known plug coupling of this type includes a coupling device having a plurality of plug pins fixed to the individual cores of the duct and held by means of circlips in apertures in the end face of the coupling device in such a way that they are rotatable and axially displaceable relative thereto. Thus, when the coupling is being put together, the plug pins can be introduced into plug apertures provided in the mating connector of the coupling. Such a coupling is fairly complicated and is relatively difficult to assemble as the coupling piece has to be screwed onto a piece of piping by means of a screw cap which in its turn is secured to the end of the duct by means of, for example, a pressure ring. When the coupling is being assembled, the coupling device is introduced into the connector, during which process the plug pins are inserted in the plug apertures, and the two parts of the coupling are interconnected by means of U-shaped spring clips which are introduced into grooves and recesses in the two coupling parts.
The main aim of the invention is to provide a plug coupling, and a coupling device therefor, which is simple and cheap to manufacture, whose installation and assembly is simple, and which is also easy to release.